wilms



Feb. 14. 1956 c. A. WILMS 2,734,733

COLLAPSIBLE BORING HEAD FOR MINING MACHINE Filed Dec. 17, 1955 3 Sheets-Sheet 1 r V IN V EN TOR.

Carl A. Wilms W4. gzemwh ATTORNEY Feb. 14, 1956 c. A. WILMS 2,734,733

COLLAPSIBLE BORING HEAD FOR MINING MACHINE Filed Dec. 1'7, 1955 3 Sheets-Sheet 2 mn 111E IN VEN TOR.

Carl A. Wilms ATTORNEY Feb. 14. 1956 c. A. WlLMS 2,734,733

COLLAPSIBLE BORING HEAD FOR MINING MACHINE Filed Dec. 17, 1953 3 Sheets-Sheet 35 ATTORNEY proceeds.

United States PatentO COLLAPSIBLE BORING HEAD FOR MINING MACHINE Carl A. Wilms, Chicago, lll.,iassignorito"Goodman Manufacturing Company, Chicago,-Ill., arcorporation of Illinois Application December 17, 1953; Serial No. 398,699

11 Claims. (.Cl. 1262-7) This invention relates to improvements in mining machines of the boring type whereinone .or more rotary boring heads are equipped with 'aplurality of cuttercarrying arms projecting'in a generally radial direction from a hub.

Among the objects of the inventionis to provide a boring head structure wherein the arms are capable of swinging from their normal working positions relative to the hub into collapsed positions of greatly reduced ing uniform movement of the-arms between their fully extended working positions and theircollapsed positions of reduced diameter.

Other objects and advantages of the invention will appear from time to time as the following description The invention may -best be understood by reference to the accompanying drawings, in which:

Figure l is a-front-view of a=boring"head'constructed in accordance with'my invention and showing :thecuttor-carrying arms thereof infully extended working 'p'osition;

Figure 2 is a view similar to Figure '1 but-showing the cutter-carrying arms in collapsed'or'contracted-posi- 'tion;

Figure 3 -is similar to Figure -2 but *showingportions ofthe hub and arms in verticalsection;

Figure 4 is an enlarged detail 'section t-aken generally on line 44 of Figure '3;

Figure 5 is an enlarged detail section taken ou line 55 of Figure '3;

"Figure 6 is a detail section taken on "line 6- 6 "of Figure '5 but drawn to a slightly larger scale.

Referring now to details of the embodiment: of -'the invention shown in the drawingsyltl indicates generally a boring head having a hub 11 with a pluralityof'arms 12,-herein three in number, extending' therefrom. The

consists ofza generally straight .inner end ,portion :19

merginginto an outer end:portion;20 which istcurved on a substantial arcin .one direction of rotationrof the boring head. The conformation of the arms is such that, when they are in fully extended cuttingposi tion as t 2,134,133 Patented Feb. 14, 1956 whileztheiouterzendscurve"outwardly from the hub in the :directionxof. normal :rotation ofthe head, as indicated by 'therarrowriniFigure '1. When the arms 12 are pivoted :into:collapsediposition.toward'the hub 11, as seen in Figure 2, the 'pivotedend members 17-are arranged to interfit with each other :in nesting relation, .so as tore- .duce'theoverall diameter of the boring head, as seen by comparison :of Figures 1 and 2.

As is usual with :boring heads of the kind to which 'this invention relates, a plurality of cutter-carrying sup ports ismounted on each of'the arms thereof. lIntthe present'invention, the outer end portion 20 of eacharm *has an-outermost -L-shaped cuttersupport 23 (-Fig. 4) projecting forwardlyfrom the extreme outer end there- -of and a second cutter support 24 projecting from the 'front face of the outer end portion 20 intermediate the first named cutter-support and the pivot pin 18. A third, innermost cutter support 25 may also be provided, in theform shown said cutter support being mounted on the front face of'the hub closely adjacent the inner end of-each pivoted arm member, as shown in Figures 1 and 4. As is usual with cutter supports of this kind, the forward ends thereof are curved on arcs which are substantially coincident with the kerfs to be cut thereby. A plurality of cutter bits 26, 26 are detachably secured as usual along thefront edges of each of said arcuate cutter bit 'supports.

Referring now 'in greater detail-to the construction of the-arms I2 and their pivoted mounting on the hub, it will be seen in Figure 4 that each hollow base 16 includesfront and rear walls 27 and 28 in which the pivot pin *18'*is-journalled.' "The outer ends-of the pivot pin are fixed in'front'and rear cheeks 29 and 30 forming partof-the straightinner end portion 19 of the pivoted arm member 17. Said cheeks engage the outer faces of the front and rear walls of base 16, as shown'in Figure 4. In the form shown-herein, the front end of the 'pivot pin 18 has a flanged head 31 countersunk in the outer face of'the front check 29 and secured to said cheek as-'by'one or more bolts'32. The rear end'of the pivot pin is keyed as at 35 in the rear cheek 30 and is securedthereto as by a retaining plate 36 and a plurality-of bolts 37, '37.

'A chain sprocket 38 is fixed as by feathering at 39 to each of the pivot pins 18 between the front and rear walls 27 *and 28 of its-respective'base 16.

Stop means are provided for limiting the hinged movementofeach of the pivoted arm members 17 so "as 'to hold'thelatter in'predetermined uniform angular relation to the "hub when the cutter head is in fully extended, operating condition. In the form shown herein, the stop means consists of a pair of bearing shoulders 40, 40a,'in each "case, formed on the hub 11, adjacent the'front and 'rear'walls 41 and 42 of the latter, in position to be engaged by stop surfaces 43, 43a formed'ionthe'inner-ends of'the front and rear cheeks 29 'and 30 of each pivoted arm member 17 when the latter are in-"fuily extended normal cutting position, as shown -in Figure 1.

Means are provided for controlling the hinged movement of the pivoted armsso that they may be moved into collapsed position-as shown inFigure 2. In theform shown-herein, said control means includes a control shaft 45 "extending axiallyof and rotatably supported "in the hollow shaft 13 of the boring head. The control shaft 45 may be provided with any suitable; means (notshown) undermanual control of the operator, for rotatingthe control rod-in either direction relative to thezhollow shaft 13. As seeminFigure 4, the front end of thecontrol Jshaft has a chain sprocket 48 fixed thereon engaged byta continuous chain 49 which is trained about each ofthe chain sprockets 38 fixed on the several pivot pins 18 which, in turn, are fixed to their respective pivoted arm members 17, as previously described. It will thus be seen that, by rotating the control shaft 45 and its chain sprocket 4% relative to the hub 11 and drive shaft 13 in a counterclockwise direction (Fig. 3), all of the pivoted arm members 17 will be simultaneously swung toward collapsed position. Conversely, when it is desired to swing the arms from their collapsed position to their fully extended cutting position, the control shaft 45 is rotated in the opposite direction to restore the arms to the fully extended cutting position shown in Figures 1 and 3.

It will further be understood that the chain 49 should be maintained in reasonably taut condition and, in particular, that it should be adjusted with respect to the three sprockets 38 so that each of the pivoted arm members 17 will reach their fully extended positions simultaneously. If the chain is not properly adjusted relative to the three sprockets to accomplish this purpose, it is possible that one or two of the arms might reach their fully extended position with the bearing shoulders 43, 43a thereon engaging the stop faces 40, 40a on the hub while the corresponding stop means on one or two of the other arms have not yet become mutually engaged. In such case, should the boring head be put into operation, the latter arm or arms would be free to swing a short distance until they engage their cooperating stop faces. This movement, when caused by engagement with the working face, might readily occur with such force as to damage or break the adjusting chain 49.

In order to provide desired relative adjustment of the chain and the chain sprockets 38, I provide a plurality of chain tension adjusting means effective on the chain between each adjacent pair of chain sprockets. One of these adjusting devices shown at the left-hand side of Figure 3 is especially designed to take care of the bight of chain which passes between the uppermost and lowermost sprockets shown in this figure and which also passes over the center sprocket 43. As shown enlarged in Fig. 5, this adjusting device consists of a cross piece 50 having a pair of. spaced roller pins 51, 51 carrying rollers 51a, 51a mounted near opposite ends thereof. Said cross piece has a shank 52 with a reduced intermediate portion 53 adapted for endwise sliding fit in a recess 53a formed at the inner end of a bore 54 extending through the hub 11, in radial alignment with the axis of rotation of said hub. Said intermediate guide portion and recess preferably have corresponding irregular guiding surfaces, such as opposed flattened faces 55 and 56, to hold the cross piece against rotation, as shown in Figure 6.

A sleeve 57 is threaded through the bore 54 in hub 11, in the form shown the hub also having an exterior boss 58 integral therewith. Said threaded sleeve is formed with a hexagonal head 59 on its outer end. A stem 60 extends through the sleeve 57 and is connected at its inner end to the shank 52 as by a cross pin 61. The outer end of said stem is threaded to receive a nut 62.

When the adjusting device is in assembled relation, as shown in Figure 5, the threaded sleeve 57 also has a large nut 63 threaded thereon between the head 59 and the outer face of the boss 58 so as to form, in effect, a lock nut for holding the threaded sleeve in various positions of endwise threaded adjustment relative to the wall of the hub through which said sleeve passes.

The adjusting means just described is such as to permit limited inward or outward positioning of the cross piece 50 with its rollers 51a, 51a by first loosening the outermost nut 62 on the outer end of stem 60 and also the larger lock nut 63 on the threaded sleeve 57, and then turning said sleeve inwardly or ontwardly to the desired position of readjustment. The sleeve may then be locked in place by tightening the lock nut 63 and the end nut 62.

A somewhat similar form of tension adjusting means is employed to take care of the chain where it passes directly from one chain sprocket 38 to an adjacent sprocket. Two of such adjusting devices 70 and 71 are shown for the right side of Figure 3. These devices are substantially the same in construction as the adjusting device previously described as located at the left side of Figure 3, excepting that, in place of a cross bar with spaced rollers, a relatively long arcuate shoe 72 is substituted, which shoe is shaped so as to conform substantially with the path of movement of the chain where it is engaged by said shoe.

The arrangement of the adjusting means described above is such that the adjusting devices are capable of independent manipulation as may be necessary to take up any slack in the chain 49 and, at the same time, to insure simultaneous engagement of the stop faces 43, 434 on all the hinged members 17 with the opposed bearing shoulders 40, 40a on the hub 11.

The use and operation of the mechanism is as follows:

By reason of the pivoted mounting of the hinged arm members 17 on their respective bases 16 and the arcuate conformation of the outer ends of said hinged arm members, as shown in Figure i, said hinged arm members are capable of being collapsed inwardly with their adjacent sides brought into an extremely close-fitting relation to each other, as shown in Figure 2, so as to reduce the overall diameter of the cutter head to a minimum. It will be observed, for instance, that the outermost cutter support 23 at the end of each hinged arm 17 projects tangentially in advance of said arm so that each arm may be folded inwardly toward the hub, with the outermost cutter support overlapping the pivot pin of the next arm and with the inner end portion 19 of each hinged arm nested closely to the outer end portion of the next arm (see Figure 2). When so folded or collapsed, the cutter arm supports 23 and 24 on the several hinged arms also fold together without interference with each other and also without interference with the innermost cutter arm supports 25 on the hub.

In operation, it will be understood that the hinged arm members 17 are normally extended to their maximum diameter for cutting, as shown in Figure 1. When it is desired to withdraw the cutter head from the working face, said cutter head is initially withdrawn a suflicient distance to free the projecting cutter supports 23, 24 and 25 from the individual kerfs which they cut in the working face while making a bore. The control mechanism for operating the chain 49 can then be actuated to swing the hinged end members 17 into the collapsed position shown in Figure 2 so as to permit the cutter head to be readily removed from the bore and also to facilitate the maneuvering of the entire machine as it may be trammed from place to place in the mine.

Although I have shown and described certain embodiments of my invention, it will be understood that I do not wish to be limited to the exact constructions shown and described, but that various changes and modifications may be made without departing from the spirit and scope of the invention as defined in the appended claims.

I claim:

1. In a boring head for mining machines, a hub having a plurality of radially projecting arms with a plurality of cutter-carrying supports projecting forwardly from each of said arms, each of said arms having hinged connection with said hub for inwardly collapsing movement toward the latter in a plane generally perpendicular to the axis thereof, the adjacent sides of said arms and the cutter-carrying supports on said arms being formed for mutually inter-fitting relation with each other for substantially the full length of said arms when in collapsed position.

2. A boring head structure in accordance with claim 1, wherein the inner ends of the hinged arms have stop faces adapted to engage bearing faces on the hub when said arms are swung outwardly to similar cutting positions relative to said hub.

3. A boring head structure in accordance with claim 1,

wherein the outer ends of the hinged arms are curved along arcs approximating that of the overall diameter of the boring head when said arms are in fully collapsed positions.

4. A boring head structure in accordance with claim 1, wherein the hub includes a hollow casing with integral hollow bases projecting radially therefrom, to which each of the hinged arms are pivotally connected, and control means is enclosed in said hollow hub and arms for causing simultaneous hinged movement of said arms relative to their respective bases.

5. A boring head structure in accordance with claim 4, wherein each of the arms is fixed on a pivot pin passing through its respective hollow base, a chain sprocket is fixed on each pivot pin within said hollow base, and an endless chain is trained over all of said chain sprockets and enclosed within said hollow bases and said hub.

6. A boring head structure in accordance with claim 5, wherein means are provided under manual control of the operator for selectively causing movement of said chain in one direction or the other relative to said hub.

7. A boring head structure in accordance with claim 6, wherein the control means includes a shaft rotatably mounted axially of said hub and having a drive sprocket thereon engaged with the chain, and wherein the shaft is rotatable under manual control independently of the rotation of said hub.

8. A boring head structure in accordance with claim 7, wherein the inner ends of the hinged arms have stop faces adapted to engage bearing faces on the hub when said arms are swung outwardly to similar cutting positions relative to said hub, and independently operable chain tensioning devices are mounted on the hub in position to engage the chain between each adjacent pair of chain sprockets.

9. A boring head structure in accordance with claim 8, wherein the chain tensioning device which engages a bight of chain directly driven by the drive sprocket of the control means includes an adjustable member having spaced bearing members adapted to span the chain sprocket and engage the chain bight at opposite sides of the chain sprocket.

10. In a boring head for mining machines, a hub, a plurality of radially projecting, cutter carrying arms hinged to said hub for inwardly collapsing movement toward said hub in a plane generally perpendicular to the axis of the latter, said hinged arms having cutter carrying supports projecting forwardly therefrom, said hub also having a plurality of fixed radially projecting arms with cuttcr carrying supports projecting forwardly therefrom, said fixed arms and their cutter carrying supports having radii shorter than the innermost radii of the cutter carrying supports on the hinged arms, all of said arms and their cutter carrying supports being formed for mutually interfitting relation with each other when the hinged arms are in collapsed position.

11. The structure of claim 10, wherein each shorter fixed arm is closely adjacent the inner end of a pivoted arm.

References Cited in the file of this patent UNITED STATES PATENTS 504,102 Claussen Aug. 29, 1893 1,427,064 Caverly Aug. 22, 1922 1,856,065 Austin May 3, 1932 

